Ok, what about the BD5

"Montblack" wrote in message
...
("John Halpenny" wrote)
Has there ever been a single seat, low cost high performance aircraft
that has been successful? I won't count the Mini 500:-)


...define high performance :-)

260 kt VNE, 200 kt cruise regularly achieved on 90-100 HP with the right
prop.



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On 1/4/2007 11:17:13 PM, Bob Martin wrote:
J.Kahn wrote:

Obviously you're dead as a doornail in a stall spin accident in either
airplane.

You could probably say that about almost any small airplane, really...


Are you saying the BD-5 will not recovery from a spin?

--
Whome?

"J.Kahn" wrote in message
...
Juan Jimenez wrote:

"J.Kahn" wrote in message
...
The lack of crashworthiness inherent in the BD 5's configuration makes
engine reliability really critical. In the end the jet version is
probably the safest one due to the better reliability of a turbojet.

Actually, both of these statements are incorrect.

These two pictures show what's left of a Canadian BD-5 that landed in a
raspberry patch and essentially tore itself apart.

http://www.bd5.com/Canada/Canada01.jpg
http://www.bd5.com/Canada/Canada02.jpg

The man holding the pieces is the builder and pilot. He walked away.
About 30% of accidents involving BD-5's are fatal. 23% of RV-6 accidents
have been fatal, and that's not counting the fact that some of those
accidents had more than one victim. You can verify that yourself on the
NTSB web site.

The Microturbo TRS-18 that is most commonly used on the BD-5J is a very
finicky engine in many respects. For example, any minor deviation on fuel
pressure can cause the engine to shut down. The fuel pumps are very
critical components, which is why at least one of the operators is
heavily involved in designing replacement components and reengineering a
portion of the fuel system to increase reliability in this area. The
irony is that even though BD-5J's are mostly used for homeland security
as cruise missile surrogates, Microturbo, with facilities in Grand
Prairie, TX, refuses to cooperate. They won't even sell parts, directly
or through the military.

I see your point Juan, although I could probably spin that around and say
it has a "76% higher fatality rate than an RV-6!"

LOL! We have another statistician in the house. God help us.

Obviously you're dead as a doornail in a stall spin accident in either
airplane. What would be interesting to see is the survival rate of BD-5
vs other homebuilts in a controlled forced landing, which when you get
down to it is the key issue that I would worry about.

I've had several friends who had engine issues and had to do forced
off-field landings. All of them walked away. I have not done the statistical
comparison, and frankly I don't have the time to find the data and run the
numbers. Maybe someone else would like to try that. The ones who have not
walked away wind up in that situation because of their own doing. For
example, a BD-5TP pilot who is doing flight tests out at Mojave and then,
out of the blue and only a few hours into phase I, decides to come back to
his home field in a dense urban area, where there are no options if you lose
the engine on takeoff. The result was regrettably predictable.

I would think the ideal engine would be a properly developed wankel.

If you added the word "installation" to the end of that sentence, then I
would agree 100%. There is a BD-5 sitting in England with a Midwest Rotary
engine. It's been ready to fly for quite some time (and actually flew with
another engine). The CAA in the UK has essentially reached the conclusion
that UK pilots are not good enough to fly the BD-5 and have refused to allow
the aircraft a renewal of the permit to fly. The problem with a rotary is
the same as with other engines in the confines of the BD-5 engine
compartment -- cooling. From what little I know about these types of
engines, they generate a lot more heat than regular piston engines, and that
places an even higher burden on heat dissipation, which the BD-5 is simply
not very good at. Getting rid of heat on a BD-5 is probably one of the most
demanding tasks for the builder.

Juan



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"Ron Wanttaja" wrote in message
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On Thu, 4 Jan 2007 10:50:29 -0600, "Whome?" wrote:

Ok, we have roasted the Mini 500, how about the BD5?

Dave "Hammer" Harris, an airshow pilot who used to fly a BD-5J at
airshows, is a
member of one of my EAA Chapters. He likes the -5 a lot, though he says
there's
a lot of things you have to correct if you start with a Bede kit. He had
the
jet for the shows, and a VW-powered version for his personal bird. Used
to fly
it to Chapter events. Went by his hangar once, and he had a third,
partially-completed model, too.

Don't know if he's still flying any of them. I know he had an engine fire
with
his VW a number of years back.

He sold the VW, and I believe it has the record for the most money paid for
a recip BD-5. Dave's airplanes are works of art, IMO.

The jet flies with these guys: http://www.smart-1.us. He's very close with
Bobby Bishop and does a lot of cruise missile surrogate work through them
for all branches of the military. In fact, Aerial Productions is a prime
contractor for the military.

Last I heard Dave was modifying a Caproni jet motorglider with a different
type of turbine engine (they originally came with Microturbo TRS-18-046.)
and had already flown it. I haven't heard anything since.

Juan



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Ron Wanttaja wrote:


And yet...40% of new homebuilts are of a type that features completely
conventional design layout, a generously-sized classic aluminum
structure carrying two people and baggage, an expensive certified
engine yet a fairly low-cost airframe, and neither the fastest nor
the shortest-landing airplane on the block. The RV line is not the
best at any one thing...but Dick VanGrunsven seems to have made the
design compromises the way most airplane owners prefer them.

This is an excellent observation and one that makes me wonder why not
certified aircraft company ever built a really successful aricraft in this
vein. The kit built market has shown that there is a market for a 2
seat+bagage aircraft that is cappable of speeds that make it useful for
travel. The RVs on the high end and even the Zenith 601XL on the low end as
it is as fast or faster than a 172 and capable of carrying 2 and "some"
bagage.

Whome? wrote:
On 1/4/2007 11:17:13 PM, Bob Martin wrote:
J.Kahn wrote:

Obviously you're dead as a doornail in a stall spin accident in
either airplane.

You could probably say that about almost any small airplane,
really...


Are you saying the BD-5 will not recovery from a spin?

It's not an "accident" if you recover.

"Whome?" wrote in message
...
On 1/4/2007 11:17:13 PM, Bob Martin wrote:
J.Kahn wrote:

Obviously you're dead as a doornail in a stall spin accident in either
airplane.

You could probably say that about almost any small airplane, really...


Are you saying the BD-5 will not recovery from a spin?

With the original wings, the BD-5 has good spin recovery. With the GAW
wings, you stand a good chance of an unrecoverable flat spin. It's been
talked about on the mailing list by people who experienced this many years
ago, and is the reason most people don't build the BD-5 with GAW wings. The
airfoil Harry Riblett suggested for the BD-5 has given good results to those
who have used them. Mine has that airfoil, but not as a reprofile -- the
original build made new ribs as part of the redesign of the wing with a
conventional spar. I'll let you know the results when it flies.

More info on this is available here http://www.bd5.com/bulletin.htm. The
last two published editions of the Bulletin (I only did a few after I took
it over, and discontinued them when the site and mailing list became fully
operational) have two articles reprinted from EAA's Sport Aviation magazine
written by the late Seth Anderson, who owned a BD-5 which he converted to
turboprop and modified in many other ways. It has a good analysis of the
flight characteristics of the BD-5. There's also a flight test report from
the late Les Berven, who was Bede's original test pilot on the BD-5 program,
here http://www.bd5.com/testberven.htm but it does not go into spin testing.

Juan



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J.Kahn wrote:
...

I would think the ideal engine would be a properly developed wankel.


You'd think that for any number of airplanes but where are they?

Rotax is selling a wankel now, maybe it will be successful.

--

FF

wrote in message
oups.com...
|
| J.Kahn wrote:
| ...
|
| I would think the ideal engine would be a properly developed wankel.
|
|
| You'd think that for any number of airplanes but where are they?
|
| Rotax is selling a wankel now, maybe it will be successful.
|
| --
|
| FF
|

Excuse me for jumping in here but I saw a wankel that a guy was
developing in Comanche, Ok. back in the '80s. He had a BD-5 in his shop
and was planning on using the wankel engine. It was a single rotor
design with enough power for the BD-5. His problem was high fuel
consumption. Exhaust temperature was another concern he had also. I
don't think he ever solved the fuel consumption problem.

The Mazda wankel actually had three times the CI that they advertised
according to an article I read at the time.

--
Jarhead




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"Juan Jimenez" wrote in
:


Tell me something I don't know.

Apparently, that you're a ****ing asshole. But don't worry - the rest of us
are quite aware of that.